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Published: Sunday, 8/31/2003

Tracking a mysterious killer

BY TAD VEZNER
SPECIAL TO THE BLADE

Deborah McCullough was shocked when she saw the southeast Michigan woodland.

“I saw trees there that were well irrigated, fertilized . but everywhere you looked, these trees were in the final stages of death,” Dr. McCullough said. “Every tree had galleries, tunnels where bugs had eaten them. And under the bark they were full of larvae. Even healthy trees - trees that should have been able to resist.”

That was a year ago, when the lead field entomologist for Michigan's Emerald Ash Borer Task Force realized what she was up against.

“I went home that night and told my husband, `this is going to be big.'”

She was right. In less than a decade, 6 million Michigan ash trees were dying. Another 4 billion in Ohio and Michigan remained at risk, all from a tiny green beetle.

Yet the battle against this new enemy was anything but straightforward. Among the troubling problems: the insect at its heart was a stranger, an alien no one seemed to recognize. Fighting invasive species is difficult enough, but how does anyone fight an enemy they can't even identify?

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A year before Dr. McCullough's tour among the dying ash trees, Dave Roberts was growing suspicious that something was very, very wrong with the ash trees around Detroit. Dr. Roberts is a plant pathologist working for Michigan State University's Extension office in Novi.

His peers dismissed his concerns, he said. He was overreacting. There were simple explanations for the dying trees, they said. If “ash yellows,” wasn't causing the blight, surely “ash decline” - a condition where ash trees die slowly for unknown reasons - was to blame. No need to worry.

But the damage was too widespread, too devastating.

“Those diseases take time. They're gradual, and not nearly so encompassing,” Dr. Roberts said. “When I went walking in some areas, I saw massive wipe-outs over vast areas, trees dying in just one year.”

Some municipalities in Southeastern Michigan - Novi, Plymouth, Dearborn, Livonia - had major problems.

“They'd cut down thousands of trees already,” Dr. Roberts said. “This was a catastrophe for them.”

Several times in 2001, Dr. Roberts applied for university funding to study the die off. Each time, he was denied.

The problem just wasn't a state priority, Keith Creagh, deputy director of the Michigan Department of Agriculture, acknowledges. They had their hands full with other pests.

“It's real easy to look for things you know about. It's much harder to look for things you don't know about,” Mr. Creagh said. “We can always do better with diagnostics.”

Finally, Dr. Roberts took the issue to the people most hurt by the dying trees. In a meeting in January, 2002, several dozen arborists and municipal council members gathered in Wayne County. The 80 people in attendance kicked in $6,500, which was enough money for Dr. Roberts to begin examining infected logs and analyzing any insects, fungi, or other disease signs uncovered.

In May, 2002, the critical clue crawled out of a log brought in for study from a residential property in Plymouth, Mich. It was a narrow, half-inch long, metallic green beetle - much different from anything Dr. Roberts had seen in his 15 years as a plant pathologist.

Many arborists said they'd seen the beetle lurking in earlier years, but had simply assumed it was native.

Dr. Roberts took the strange green bug in his hand - the first of many adult beetles he and the arborists working with him would collect from the countryside in the succeeding weeks - and began studying it.

Less than a month later, he was certain he needed some real help.

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Ask an average person how many types of beetles there are in the world, and they'll intuitively tell you, “a lot.”

These Emerald Ash Borers are stored in the Michigan State University Natural Science Building. These Emerald Ash Borers are stored in the Michigan State University Natural Science Building.
LISA DUTTON / BLADE Enlarge

Gary Parsons is an expert on exactly how many “a lot” of beetles are. As collection manager at MSU's department of entomology - and a beetle specialist to boot - he's quick to point out that there are at least 171 species of beetle native

to North America - not counting those in Mexico, where some experts will tell you there are “a lot more.”

In all, Mr. Parsons says, beetles make up a full quarter of the living things on the planet.

So when an official from MSU Extension walked into Mr. Parsons' office on June 19, 2002, and asked him to identify a strange, green beetle, Mr. Parsons launched his search for a beetle in a tray-stack - a tray-stack containing 2.5 million insects, carefully secured and labeled in hundreds of glass-topped cabinets and drawers.

Entomologists from around the world use MSU's vast insect collection.

Despite the dizzying array of beetles to review, Mr. Parson's met with some early success.

“I recognized the genus as Agrilus immediately, based on its size and cylindrical shape,” Mr. Parsons said. In an instant, he was 80 percent done.

By identifying the genus, he'd taken four of the five steps needed to scientifically categorize a living organism.

He knew the beetle's class (Insecta) - Step One. That was easy. Step Two, the order, was easy too. All beetles belong to the order Coleoptera. For a beetle expert like Mr. Parson's, Step Three, the family name - Buprestidae - wasn't too tough. Finding the genus, Step Four, demanded real expertise.

But that left one last step - species - the final identifier.

For hours, Mr. Parsons struggled to find the species. But there was always something wrong. The beetle was too big. Its green body was too bright. It feasted on the wrong type of tree.

The only thing even close in Mr. Parsons' 347-page manual on North American Agrilus beetles, published in 1928, was something way out in Arizona. Something that wouldn't think about biting into an ash tree. And certainly not something capable of threatening millions upon millions of ash trees in a matter of years.

By the end of the day, Mr. Parsons was worried. He picked up the phone.

“Once things didn't jive here, everything hit the fan,” Mr. Parsons said.

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Now the major players stepped in. The U.S. Department of Agriculture's Animal & Plant Health Inspection Service (APHIS), the state Department of Natural Resources (DNR), the Michigan Department of Agriculture (MDA), an alphabet soup of government entities all of the sudden needed to know about the tiny green beetle from southeast Michigan.

The Smithsonian Institution in Washington and the British National Museum -- the two largest insect collections in the western world - joined the identification effort.

“Normally Gary [Parsons] can identify any sort of beetle,” Dr. McCullough said. “We got a bad feeling after a couple of days.”

She also searched hundreds of journals herself, looking for a clue, with no success.

In three weeks, officials at the Smithsonian Institution realized they were looking at a beetle even they had never seen before.

Now, it was time for the Smithsonian to summon higher powers. Richard Westcott, a taxonomist emeritus and full-time volunteer for the Oregon Department of Agriculture, specializes in Buprestidae beetles. Could he identify the elusive beetle?

For nearly 60 years - since he was 4 - Mr. Westcott has collected beetles, abandoning the butterflies that broke apart in his tiny hands. Plus he loved beetles for their gaudiness, and their diversity. The Agrilus genus - to which this new beetle belonged - was the largest and most diverse genus of any organism in the world.

When the call came in, Mr. Westcott was getting ready for a trip to Mexico, where more than 600 species of Agrilus beetles reside.

E-mailed photos of Michigan's mystery beetle didn't tell half the story, he realized. He couldn't see the exact angles at which the legs connected to the body, nor tell how indented the beetle's outer shell was, nor how many segments were in that shell. He needed the real deal.

Upon receiving the beetle, he unwrapped its package and looked down inquisitively - just as he'd looked at his first beetle, 57 years ago.

It was like no beetle he'd seen in his life.

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This demanded international diplomacy.

“I thought it might be from Asia - only because that's where everything else like this was coming from,” Mr. Westcott said.

Mr. Westcott suggested the Smithsonian enlist the aid of his colleague - a member of what he calls “the international bug club” - Eduardo Jendick of the Institute of Zoology at the Slovak Academy of Sciences in Bratislava, Slovakia. Dr. Jendick had just written a revisionist work on Asian Agrilus beetles.

Dr. Jendick studied the Michigan beetle's picture, and heard about its destructive ways. But he had to have the beetle. He demanded its delivery.

The 4,000 mile journey brought an answer. On July 9th, 2002, the hunt was over.

After a few pokes and prods, Dr. Jendick identified the new beetle's species as planipennis (Latin for flat-winged), native to China, Japan, and Russia.

And yet, what was done wasn't really done. Yes, they had a name, but neither Dr. Jendick nor anyone else knew the creature's biology: what it ate, when it mated, how it developed, and, most important, what could stop it.

So the discovery, however exciting, didn't spark a cascade of cartwheels in the scientific community. Many feared they would never find details of this bug's life, since so much important literature was destroyed during the Chinese Cultural Revolution. Most experts believed the beetle came in from China.

Back in America, Bob Haack - head research entomologist for the USDA Forest Service's North-Central Research Station - resorted to paging through a 1,362-page book he'd picked up on a recent trip to China.

It was a gift from the Chinese Academy of Forestry given to him in the summer of 2000 while he researched the Asian Long Horn Beetle - another invasive Chinese pest imported to America.

Unfortunately, the book, entitled “Forest Insects of China,'' was in Chinese. He couldn't read it.

Fortunately, one of his research assistants, Hou Ping Liu, could.

And on page 400, Dr. Liu found a beetle that could only be Agrilus planipennis (called Agrilus marcopoli in China). Here were details on its life cycle - how it develops, feeds, grows, and mates.

There were other details: how the adults will defensively “play dead” if disturbed; how a female can produce 60 to 90 eggs in her lifetime, and how, if left unchecked, severe infestations can destroy stands of Manchurian and Chinese ash trees.

It was the first major step in what would soon become a rush to discover more about the beetle that came to be called the “Emerald Ash Borer,” due to its color and taste in food.

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One year after the discovery, $14.15 million was allocated to the United States Department of Agriculture to “isolate and eradicate” the beetle. Over the next 12 years, USDA expects to receive $368 million to combat the pest, lest it destroy every single one of the estimated 600 million ash trees still living in Michigan, as well as the 3.8 billion ash trees that stand mostly undisturbed in Ohio.

No one yet knows how the original emerald ash borers came to the region. Many, including Dr. McCullough, believe it arrived in a Great Lakes port five to 10 years ago.



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